Surface plasmon resonance biosensors for detection of Alzheimer disease biomarker

This paper describes direct label-free detection of 17beta-hydroxysteroid dehydrogenase type 10 (17β-HSD10) using a surface plasmon resonance (SPR) biosensor. This multifunctional mitochondrial enzyme is involved in pathogenesis of Alzheimer disease (AD) and represents a potential target for AD diagnostics. A multichannel SPR sensor with spectral modulation is functionalized with amyloid beta or polyclonal antibody against 17β-HSD10 peptide using a self-assembled monolayer of alkylthiolates and amino coupling chemistry. Detection of a synthetic peptide of 14 amino acids from the 17β-HSD10 molecule (residues 133–146 aa) and whole enzyme 17β-HSD10 is performed. Detection of 17β-HSD10 enzyme in artificial cerebrospinal fluid (ACSF) buffer is also carried out. It is demonstrated that the reported SPR biosensor is capable of detecting 17β-HSD10 enzyme at ng/ml levels.